Check the anti-theft numbers(e-mail the owner)aka belly numbers. If the vin numbers are legit (not possible) the anti-theft numbers should match on each case half and correspond to the Vin year. In other words the vin year should correspond to the last two digits of the anti-theft numbers. This is the best way to determine whether or not a set of numbers are legit,I have used this method on every bike ('59XL I bought since 1970)

Mark,every set of cases I've ever seen with legit numbers correspond,you missed what I said. 'Back in the day" everyone called the line-bore numbers anti-theft numbers this was WAY before the interenet and this forum. As someone else has said I still think it is 1970 and Bronson is on TV.

The KHR was assembled in the HD Race Department alongside the KR. Production numbers do not apply. I have seen some KRs with standard line bore numbers on the bottoms and some with only several matching digits on each case half ( I always thought these were motors built from cases, not complete racers assembled at the Race Shop). Tradition in the Race Department for WR and KR race motors was to have the blank cases stamped with vin numbers in the shop where they used a different font than was used on the production line. For a really good look at Race Shop numbers check out the Beauty of Speed website WR Registry under the Paddock heading. The only way to tell for sure if this is a genuine KHR is to pull the primary chain cover and look at the sprocket shaft and seal. The sprocket shaft should be a tapered shaft with a key and have the domed oil slinger as used on the WR/KR. Providing the cylinders are the taller (longer stroke) KHR parts (they have the correct exhaust ports) and the cams are running in single row ball bearings, it is probably a real deal KHR motor. Pretty rare. This motor would seem to have the correct line bore numbers for the year (556-65). Outside of the motor, the rest of the motorcycle is made up of later aftermarket racing parts, so I would not call it a restoration. I know a little bit about these motorcycles, but I'm surely not an expert. I think I have hit on most the stuff that makes this unique.

Beachdog,I agree with you on the rare parts,i.e. the LATE KHR cylinders. Which I've only seen one NOS set at Davenport,which Dale Walksler bought years ago. I don't mean to argue but you contradict yourself on the Beauty of Speed website. There are NO WR numbers in the 5000 range, also check out Patrick's WEB( the french owl) which there are NO KR,KHK.KK,K,KHRTT vin #'s in the 5000.

Confirming the long stroke would be a given for a prospective buyer. The reference to BOS was simply to illustrate the different number font used by the Race Shop, not a reference to the high vin number used on this motor. Not trying to start an argument. Having said this, both of you (Brewski & Rubone) have long experience with HD racers. My long experience has forced me to accept one thing for sure, never say never when it comes to the Race Department.

True race shop motors did not have the boss on top of the primary drilled and taped. it was just a bare boss. This motor probably has a replacement rightside crankcase, also unlike the KR's the cylinders just have a 54 without an R in the casting. Since most people did not see the "R" on the cylinders they often got mistaken as KHRM cylinders but were not the same. also the motor numbers from the race shop had a heel and toe on the bottom of the letters.

All, thanks for the comments and input so far. tghook I have seen your bikes in earlier posts: Beauties!!!I don’t understand your statement: ”True race shop motors did not have the boss on top of the primary drilled and taped. it was just a bare boss” Are you talking about drilled and threaded hole in the little boss on the primary just on top of the clutch section of the primary cast?Have been I touch with the gentleman selling. He confirms the cylinders have casting numbers 16561-54 front and 16581-54 rear. These are the same number as my KH cylinders have. Front cylinder has in addition a cast boss with K-2-3 on. GuS

To me this is a KH set of cases with the R added much later, way too high serial... The background of the serial pad looks a bit "flat" compared to the rest of the cases... And never mind the XR cycle parts... Easrly KRs were indeed stamped in sequence with the std street K and KH but that soon disappeared. Problem is when... BUT they never sold 6000 KH in 56, that's deffo. Also I've never been given a K or KH serial higher than just under 3000... We know for sure just under 2000 made each year, 52 to 56.

Race belly numbers never follow the street codes. I haven't seen that many, but what I've seen as proper race bellies have been just digits, in the teens or hundred, say 16 on both sides or 233 on both sides... No model code or year... Soi if this one has a proper coded belly, it confirms to me it is street cases.

He confirms the cylinders have casting numbers 16561-54 front and 16581-54 rear

These are street KH casting numbers. KHRM would have used these cyls, but not the KHR which is a ball bearing proper race engine. Don't know what the casting number would be for KHR cyls, but would for sure end with an R and feature the thickended base as per corresponding KR cyls...

Hi Patrick, I've been told by people who should know that the KHRs did have the standard KH numbers on the base, but had the female spigot and presumably some relieving work done - though never seen a set to confirm myself.

Numbers do seem to be incorrect, but a nice bike overall despite it - prefer mine a bit less "restored" though!

AllThanks again, always learning hereI have received these pictures from the seller. Right side has R in casting. Cams are ball bearing and seem to have racing lobes. Left side case I cannot tell. Flywheel and rods seems to be standard KH.